B(C6F5)3 catalysis accelerates the hydrosilane chlorination by Ph3CCl

0492087 - ÚFCH JH 2019 GB eng J - Journal Article
Šimarek, A. - Lamač, Martin - Horáček, Michal - Pinkas, Jiří
B(C6F5)3 catalysis accelerates the hydrosilane chlorination by Ph3CCl.
Applied Organometallic Chemistry. Roč. 32, č. 8 (2018), č. článku e4442. ISSN 0268-2605. E-ISSN 1099-0739
R&D Projects: GA ČR(CZ) GA17-13778S
Institutional support: RVO:61388955
Keywords : hydrosilane chlorination * B(C6F5)3 catalysis * chlorosilanes
OECD category: Physical chemistry
Impact factor: 3.259, year: 2018

A chlorination of tertiary (5 examples), secondary (3 examples) and primary (PhSiH3) hydrosilanes by Ph3CCl with a catalytic amount of B(C6F5)3 is presented. The reaction was substantially faster than its non‐catalyzed version. The chlorination of secondary hydrosilanes and PhSiH3 proceeded in a stepwise manner, which allowed selective isolation of chlorohydrosilanes. The mechanism of catalytic hydrosilane chlorination seems to be distinct to mainstream B(C6F5)3 catalyzed reactions involving hydrosilanes (i.e. activation of Si‐H bond by the R3Si‐‐H‐‐B (C6F5)3 adduct formation). Contrary, the present process is based on an instant formation of [Ph3C]+[ClB(C6F5)3]− from B(C6F5)3 and Ph3CCl, followed by a hydride transfer from particular hydrosilane to tritylium cation with a concomitant generation of unstable
silylium cation compensated by borate anion [ClB(C6F5)3]−. Subsequent decomposition of this ionic species leads to the corresponding chlorosilane and recuperation of B(C6F5)3.
Permanent Link: http://hdl.handle.net/11104/0285649